Thoughts on Building a Connected Digital World, and Math Trivia

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Posted in October 2013 …

#math trivia for #September21: #264 is the sum of a square and a cube, and also of two squares and a cube. What are they? — Burt Kaliski Jr. (@modulomathy) September 22, 2013 Answer: The square and cube are 256 = 162 and 8 = 23. The two squares and cube are 4 = 22, … Continue reading →

#math trivia for #June11: #163 has three different digits where two (1,3) divide into the other (6). What’s the next number like this? — Burt Kaliski Jr. (@modulomathy) June 12, 2012 The next number with three different digits where two divide into the other is 182. Several numbers in between satisfy the divisibility requirement, but … Continue reading →

#math trivia for #September18: #261 = 29*9; September is the 9th month. Is day 29*M always in month M? What about other multiples of M? — Burt Kaliski Jr. (@modulomathy) September 19, 2013 Yes, day 29*M is always in month M: Day 29: January 29 Day 58: February 27 Day 87: March 28 Day 116: … Continue reading →

#math trivia for #September16: #259 has two squares side by side. Do any day-numbers have two squares overlapping? — Burt Kaliski Jr. (@modulomathy) September 17, 2013 The side-by-side squares are of course 25 and 9. The problem doesn’t state exactly how much overlapping is allowed, so many forms are possible. Presumably, every digit is involved … Continue reading →

#math trivia for #September17: #260 is number of license plates with letter then number. How many if both digits can be letter or number? — Burt Kaliski Jr. (@modulomathy) September 18, 2013 The count of 260 comes from the product of the number of letters, A-Z, which is 26, and the number a single-digit numbers, … Continue reading →

#math trivia for #September15: #258 consists of three digits in an arithmetic progression. Which other numbers in the 200s do? — Burt Kaliski Jr. (@modulomathy) September 16, 2013 The digits 2, 5 and 8 form an arithmetic progression because each successive pair has the same difference: 5-2 = 8-5 = 3. The answers consist … Continue reading →